Controversies in neuroimmunology: Multiple sclerosis and other demyelinating disorders

Multiple sclerosis is the most prevalent demyelinating disease affecting the central nervous system. In the past two decades, significant milestones have been achieved in this domain, including the identification of critical immunological pathways, novel biomarkers, and effective immunotherapies. Nonetheless, several areas of uncertainty and challenges persist. Globally, there has been a notable increase in multiple sclerosis cases. In Colombia, recent studies indicate a rise in prevalence from fewer than 5 cases per 100 000 inhabitants to 7.5 cases per 100 000. It is imperative for neurologists to stay informed about current treatments to offer appropriate guidance to these patients. This review analyzes eight pertinent controversies surrounding multiple sclerosis, and other demyelinating diseases, based on the most current scientific evidence. Topics explored include: 1) prevention of postpartum relapses, 2) neuromyelitis optica spectrum disorder, 3) the role of genetic testing in diagnosis, 4) risks of malignancy associated with immunotherapy, 5) discontinuation of treatment in older adults, 6) management strategies for lymphopenia, 7) what is the indication for stem cell therapy in multiple sclerosis? and 8) approaches to mitigate rebound effects after discontinuing disease-modifying therapy. Each controversy is supported by a thorough analysis and practical recommendations aimed at informing decision-making in daily clinical practice and adapting to the realities of countries like ours, where advancements in neurological training and access to treatments are crucial.